1. Field of the Invention
The present invention relates to a high alignment order and high crystallinity polythiophene nanowire for organic solar panels and to a method of preparation thereof, especially to use of a high crystalline polythiophene nanowire with high alignment and high crystallinity to elevate light conversion efficiency of organic solar panels.
2. The Prior Arts
Currently, materials for active layer of organic solar panels are principally prepared by mixing and dissolving poly(3-hexylthiophene) (P3HT) and carbon-based nano-materials (e.g. phenyl-C61-butyric acid methyl ester (PCBM), carbon nano-tube (e.g. SWCNT and MWCNT) or mixtures thereof) in organic solvents, subsequently coating the resulting mixture to generate an active layer in bulk-heterojunctions (BHJ) and then using thermal treatment technique to reinforce the structure of the active layer of organic solar panels.
With regard to polythiophene nanowire for organic solar panels and prior arts for its preparation, as disclosed in Taiwan (ROC) Patent No. 201316582 “organic thin-film solar cells and method of preparation thereof”, both p-type semiconductor materials (electron donors) and n-type semi-conductor materials (electron acceptors) made out of organic materials were separated from each other by means of phase separation and a bulk heterojunction (BHJ) that could convert light energy into electrical energy was generated in this way.
In the active layers prepared by phase separation technique from the prior arts, polythiophene molecules assembled themselves into polythiophene nano-whiskers in three-dimensional network structure. However, the crystallinity of the polythiophene nanowhiskers prepared by this method (as shown in FIG. 8) was very low (about 30%) and could not be effectively elevated even though they were submitted to subsequent thermal treatment process. And this was reason why the light conversion efficiency of organic solar panels prepared by this method was merely between 2% and 5%.